If there is neither a panel nor a bridge, the display timing can be
parsed from the display-timings node under the dp node.

In order to get rid of &analogix_dp_plat_data.get_modes() and make
the codes more consistent, apply DRM legacy bridge to parse display
timings.

Signed-off-by: Damon Ding <damon.ding@rock-chips.com>

------

Changes in v6:
- Apply DRM legacy bridge to parse display timings intead of
  implementing the same codes only for Exynos DP.
---
 drivers/gpu/drm/exynos/Kconfig     |  1 +
 drivers/gpu/drm/exynos/exynos_dp.c | 71 +++++++++---------------------
 2 files changed, 22 insertions(+), 50 deletions(-)

diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
index 0d13828e7d9e..66665d317848 100644
--- a/drivers/gpu/drm/exynos/Kconfig
+++ b/drivers/gpu/drm/exynos/Kconfig
@@ -72,6 +72,7 @@ config DRM_EXYNOS_DP
 	select DRM_ANALOGIX_DP
 	select DRM_DISPLAY_DP_HELPER
 	default DRM_EXYNOS
+	select DRM_LEGACY_BRIDGE
 	select DRM_PANEL
 	help
 	  This enables support for DP device.
diff --git a/drivers/gpu/drm/exynos/exynos_dp.c b/drivers/gpu/drm/exynos/exynos_dp.c
index e20513164032..507d0a98fe5b 100644
--- a/drivers/gpu/drm/exynos/exynos_dp.c
+++ b/drivers/gpu/drm/exynos/exynos_dp.c
@@ -19,6 +19,7 @@
 #include <video/videomode.h>
 
 #include <drm/bridge/analogix_dp.h>
+#include <drm/bridge/legacy-bridge.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
 #include <drm/drm_crtc.h>
@@ -38,11 +39,23 @@ struct exynos_dp_device {
 	struct drm_device          *drm_dev;
 	struct device              *dev;
 
-	struct videomode           vm;
 	struct analogix_dp_device *adp;
 	struct analogix_dp_plat_data plat_data;
 };
 
+static int exynos_dp_legacy_bridge_init(struct exynos_dp_device *dp,
+					struct drm_bridge **bridge)
+{
+	if (!bridge)
+		return -EINVAL;
+
+	*bridge = devm_drm_legacy_bridge(dp->dev, dp->dev->of_node, DRM_MODE_CONNECTOR_eDP);
+	if (IS_ERR(*bridge))
+		return PTR_ERR(*bridge);
+
+	return 0;
+}
+
 static int exynos_dp_crtc_clock_enable(struct analogix_dp_plat_data *plat_data,
 				bool enable)
 {
@@ -67,44 +80,20 @@ static int exynos_dp_poweroff(struct analogix_dp_plat_data *plat_data)
 	return exynos_dp_crtc_clock_enable(plat_data, false);
 }
 
-static int exynos_dp_get_modes(struct analogix_dp_plat_data *plat_data,
-			       struct drm_connector *connector)
-{
-	struct exynos_dp_device *dp = to_dp(plat_data);
-	struct drm_display_mode *mode;
-
-	if (dp->plat_data.panel)
-		return 0;
-
-	mode = drm_mode_create(connector->dev);
-	if (!mode) {
-		DRM_DEV_ERROR(dp->dev,
-			      "failed to create a new display mode.\n");
-		return 0;
-	}
-
-	drm_display_mode_from_videomode(&dp->vm, mode);
-	connector->display_info.width_mm = mode->width_mm;
-	connector->display_info.height_mm = mode->height_mm;
-
-	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
-	drm_mode_set_name(mode);
-	drm_mode_probed_add(connector, mode);
-
-	return 1;
-}
-
 static int exynos_dp_bridge_attach(struct analogix_dp_plat_data *plat_data,
 				   struct drm_bridge *bridge,
 				   struct drm_connector *connector)
 {
 	struct exynos_dp_device *dp = to_dp(plat_data);
+	enum drm_bridge_attach_flags flags = 0;
 	int ret;
 
 	/* Pre-empt DP connector creation if there's a bridge */
 	if (plat_data->next_bridge) {
-		ret = drm_bridge_attach(&dp->encoder, plat_data->next_bridge, bridge,
-					0);
+		if (drm_bridge_is_legacy(plat_data->next_bridge))
+			flags = DRM_BRIDGE_ATTACH_NO_CONNECTOR;
+
+		ret = drm_bridge_attach(&dp->encoder, plat_data->next_bridge, bridge, flags);
 		if (ret)
 			return ret;
 	}
@@ -129,19 +118,6 @@ static const struct drm_encoder_helper_funcs exynos_dp_encoder_helper_funcs = {
 	.disable = exynos_dp_nop,
 };
 
-static int exynos_dp_dt_parse_panel(struct exynos_dp_device *dp)
-{
-	int ret;
-
-	ret = of_get_videomode(dp->dev->of_node, &dp->vm, OF_USE_NATIVE_MODE);
-	if (ret) {
-		DRM_DEV_ERROR(dp->dev,
-			      "failed: of_get_videomode() : %d\n", ret);
-		return ret;
-	}
-	return 0;
-}
-
 static int exynos_dp_bind(struct device *dev, struct device *master, void *data)
 {
 	struct exynos_dp_device *dp = dev_get_drvdata(dev);
@@ -151,12 +127,6 @@ static int exynos_dp_bind(struct device *dev, struct device *master, void *data)
 
 	dp->drm_dev = drm_dev;
 
-	if (!dp->plat_data.panel && !dp->plat_data.next_bridge) {
-		ret = exynos_dp_dt_parse_panel(dp);
-		if (ret)
-			return ret;
-	}
-
 	drm_simple_encoder_init(drm_dev, encoder, DRM_MODE_ENCODER_TMDS);
 
 	drm_encoder_helper_add(encoder, &exynos_dp_encoder_helper_funcs);
@@ -223,6 +193,8 @@ static int exynos_dp_probe(struct platform_device *pdev)
 	}
 
 	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &panel, &bridge);
+	if (ret == -ENODEV)
+		ret = exynos_dp_legacy_bridge_init(dp, &bridge);
 	if (ret)
 		return ret;
 
@@ -233,7 +205,6 @@ static int exynos_dp_probe(struct platform_device *pdev)
 	dp->plat_data.power_on = exynos_dp_poweron;
 	dp->plat_data.power_off = exynos_dp_poweroff;
 	dp->plat_data.attach = exynos_dp_bridge_attach;
-	dp->plat_data.get_modes = exynos_dp_get_modes;
 	dp->plat_data.skip_connector = !!bridge;
 
 out:
-- 
2.34.1

On Tue, Sep 30, 2025 at 05:09:09PM +0800, Damon Ding wrote:
> If there is neither a panel nor a bridge, the display timing can be
> parsed from the display-timings node under the dp node.
> 
> In order to get rid of &analogix_dp_plat_data.get_modes() and make
> the codes more consistent, apply DRM legacy bridge to parse display
> timings.
> 
> Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
> 
> ------
> 
> Changes in v6:
> - Apply DRM legacy bridge to parse display timings intead of
>   implementing the same codes only for Exynos DP.
> ---
>  drivers/gpu/drm/exynos/Kconfig     |  1 +
>  drivers/gpu/drm/exynos/exynos_dp.c | 71 +++++++++---------------------
>  2 files changed, 22 insertions(+), 50 deletions(-)
> 
> diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
> index 0d13828e7d9e..66665d317848 100644
> --- a/drivers/gpu/drm/exynos/Kconfig
> +++ b/drivers/gpu/drm/exynos/Kconfig
> @@ -72,6 +72,7 @@ config DRM_EXYNOS_DP
>  	select DRM_ANALOGIX_DP
>  	select DRM_DISPLAY_DP_HELPER
>  	default DRM_EXYNOS
> +	select DRM_LEGACY_BRIDGE
>  	select DRM_PANEL
>  	help
>  	  This enables support for DP device.
> diff --git a/drivers/gpu/drm/exynos/exynos_dp.c b/drivers/gpu/drm/exynos/exynos_dp.c
> index e20513164032..507d0a98fe5b 100644
> --- a/drivers/gpu/drm/exynos/exynos_dp.c
> +++ b/drivers/gpu/drm/exynos/exynos_dp.c
> @@ -19,6 +19,7 @@
>  #include <video/videomode.h>
>  
>  #include <drm/bridge/analogix_dp.h>
> +#include <drm/bridge/legacy-bridge.h>
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_bridge.h>
>  #include <drm/drm_crtc.h>
> @@ -38,11 +39,23 @@ struct exynos_dp_device {
>  	struct drm_device          *drm_dev;
>  	struct device              *dev;
>  
> -	struct videomode           vm;
>  	struct analogix_dp_device *adp;
>  	struct analogix_dp_plat_data plat_data;
>  };
>  
> +static int exynos_dp_legacy_bridge_init(struct exynos_dp_device *dp,
> +					struct drm_bridge **bridge)
> +{
> +	if (!bridge)
> +		return -EINVAL;

Well, this can't happen, can it?

> +
> +	*bridge = devm_drm_legacy_bridge(dp->dev, dp->dev->of_node, DRM_MODE_CONNECTOR_eDP);
> +	if (IS_ERR(*bridge))
> +		return PTR_ERR(*bridge);
> +
> +	return 0;
> +}

I'd suggest inlining the function. It doesn't make sense to have
one-line wrapper.

> +
>  static int exynos_dp_crtc_clock_enable(struct analogix_dp_plat_data *plat_data,
>  				bool enable)
>  {

[...]

>  static int exynos_dp_bridge_attach(struct analogix_dp_plat_data *plat_data,
>  				   struct drm_bridge *bridge,
>  				   struct drm_connector *connector)
>  {
>  	struct exynos_dp_device *dp = to_dp(plat_data);
> +	enum drm_bridge_attach_flags flags = 0;
>  	int ret;
>  
>  	/* Pre-empt DP connector creation if there's a bridge */
>  	if (plat_data->next_bridge) {
> -		ret = drm_bridge_attach(&dp->encoder, plat_data->next_bridge, bridge,
> -					0);
> +		if (drm_bridge_is_legacy(plat_data->next_bridge))

I see... You are going to kill this line in one of the next patches, but
the API will stay. I suggest adding a flag to the exynos_dp_device and
then removing the flag once you migrate to drm_bridge_connector.

> +			flags = DRM_BRIDGE_ATTACH_NO_CONNECTOR;
> +
> +		ret = drm_bridge_attach(&dp->encoder, plat_data->next_bridge, bridge, flags);
>  		if (ret)
>  			return ret;
>  	}

-- 
With best wishes
Dmitry

Hi Dmitry,

On 10/1/2025 4:17 AM, Dmitry Baryshkov wrote:
> On Tue, Sep 30, 2025 at 05:09:09PM +0800, Damon Ding wrote:
>> If there is neither a panel nor a bridge, the display timing can be
>> parsed from the display-timings node under the dp node.
>>
>> In order to get rid of &analogix_dp_plat_data.get_modes() and make
>> the codes more consistent, apply DRM legacy bridge to parse display
>> timings.
>>
>> Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
>>
>> ------
>>
>> Changes in v6:
>> - Apply DRM legacy bridge to parse display timings intead of
>>    implementing the same codes only for Exynos DP.
>> ---
>>   drivers/gpu/drm/exynos/Kconfig     |  1 +
>>   drivers/gpu/drm/exynos/exynos_dp.c | 71 +++++++++---------------------
>>   2 files changed, 22 insertions(+), 50 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
>> index 0d13828e7d9e..66665d317848 100644
>> --- a/drivers/gpu/drm/exynos/Kconfig
>> +++ b/drivers/gpu/drm/exynos/Kconfig
>> @@ -72,6 +72,7 @@ config DRM_EXYNOS_DP
>>   	select DRM_ANALOGIX_DP
>>   	select DRM_DISPLAY_DP_HELPER
>>   	default DRM_EXYNOS
>> +	select DRM_LEGACY_BRIDGE
>>   	select DRM_PANEL
>>   	help
>>   	  This enables support for DP device.
>> diff --git a/drivers/gpu/drm/exynos/exynos_dp.c b/drivers/gpu/drm/exynos/exynos_dp.c
>> index e20513164032..507d0a98fe5b 100644
>> --- a/drivers/gpu/drm/exynos/exynos_dp.c
>> +++ b/drivers/gpu/drm/exynos/exynos_dp.c
>> @@ -19,6 +19,7 @@
>>   #include <video/videomode.h>
>>   
>>   #include <drm/bridge/analogix_dp.h>
>> +#include <drm/bridge/legacy-bridge.h>
>>   #include <drm/drm_atomic_helper.h>
>>   #include <drm/drm_bridge.h>
>>   #include <drm/drm_crtc.h>
>> @@ -38,11 +39,23 @@ struct exynos_dp_device {
>>   	struct drm_device          *drm_dev;
>>   	struct device              *dev;
>>   
>> -	struct videomode           vm;
>>   	struct analogix_dp_device *adp;
>>   	struct analogix_dp_plat_data plat_data;
>>   };
>>   
>> +static int exynos_dp_legacy_bridge_init(struct exynos_dp_device *dp,
>> +					struct drm_bridge **bridge)
>> +{
>> +	if (!bridge)
>> +		return -EINVAL;
> 
> Well, this can't happen, can it?
> 
>> +
>> +	*bridge = devm_drm_legacy_bridge(dp->dev, dp->dev->of_node, DRM_MODE_CONNECTOR_eDP);
>> +	if (IS_ERR(*bridge))
>> +		return PTR_ERR(*bridge);
>> +
>> +	return 0;
>> +}
> 
> I'd suggest inlining the function. It doesn't make sense to have
> one-line wrapper.
> 

Will do in v7.

>> +
>>   static int exynos_dp_crtc_clock_enable(struct analogix_dp_plat_data *plat_data,
>>   				bool enable)
>>   {
> 
> [...]
> 
>>   static int exynos_dp_bridge_attach(struct analogix_dp_plat_data *plat_data,
>>   				   struct drm_bridge *bridge,
>>   				   struct drm_connector *connector)
>>   {
>>   	struct exynos_dp_device *dp = to_dp(plat_data);
>> +	enum drm_bridge_attach_flags flags = 0;
>>   	int ret;
>>   
>>   	/* Pre-empt DP connector creation if there's a bridge */
>>   	if (plat_data->next_bridge) {
>> -		ret = drm_bridge_attach(&dp->encoder, plat_data->next_bridge, bridge,
>> -					0);
>> +		if (drm_bridge_is_legacy(plat_data->next_bridge))
> 
> I see... You are going to kill this line in one of the next patches, but
> the API will stay. I suggest adding a flag to the exynos_dp_device and
> then removing the flag once you migrate to drm_bridge_connector.
> 

Yes, using a temporary flag is a better approach.

>> +			flags = DRM_BRIDGE_ATTACH_NO_CONNECTOR;
>> +
>> +		ret = drm_bridge_attach(&dp->encoder, plat_data->next_bridge, bridge, flags);
>>   		if (ret)
>>   			return ret;
>>   	}
> 

Best regards,
Damon